In the known devices of the indicated type the fluid subjected to measurement is supplied, through a tubular inlet, to a detection chamber of the casing, accommodated in which is the sensor, in such a manner that the latter detects the pressure of the fluid. The body of the sensor has a membrane portion and is welded or rigidly fixed into the chamber, typically at the tubular inlet or on the circuit support. The pressure of the fluid is such to cause a flexure of the membrane portion of the sensor and the amount of such flexure, which depends on the pressure of the fluid, is measured through a detection element provided for on the membrane portion. The output signal generated by the detection element, representing the pressure value, is preferably processed and/or amplified and/or conditioned by a circuit arrangement, which may comprise a printed circuit board directly accommodated in the casing of the device. The device is connected—by means of a connector—to an external system, such as for example an automobile engine control unit.
The known devices of the indicated type have a relatively complex structure, they have reliability problems in the long-term and they are difficult to produce from an industrial point of view. Production of such devices is difficult to automate due to the small dimensions and the inherent delicateness of the interior components, and specifically the dimensions of the pressure sensor and of the possible printed circuit board.